Cooling System

ABSTRACT

A cooling system including a ventilator that exchanges atmosphere between parts of a building that are at differing heights. The ventilator includes an outer conduit that extends from an upper end thereof downward to a lower end thereof. An inner conduit extends substantially the entire length of the outer conduit. Both the outer and inner conduits are open at their respective upper ends and lower ends. Temperatures of atmosphere both surrounding and within the outer conduit and the inner conduit induce an exchange of atmosphere between the ventilator and surrounding atmosphere.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national application claiming priority benefit toAustralian patent application No 2017261629. The foregoing Australianpatent application is related to the following prior patentapplications: Australian patent application No. 2016203886; Australianpatent application No. 2015202537 (which claims priority from U.S.provisional patent application No 61/991,436); PCT patent applicationNo. PCT/US2014/033101. The contents of all these applications areincorporated herein by reference.

BACKGROUND Technical Field

The present disclosure relates generally to a cooling system forbuilding ventilation and, more particularly, to a ventilation systemthat exploits a temperature difference between a building's interior andthe surrounding atmosphere.

Background Art

Any discussion of documents, acts, materials, devices, articles and thelike in this specification is included solely for the purpose ofproviding a context for the present invention. It is not suggested orrepresented that any of these matters formed part of the prior art baseor were common general knowledge in the field relevant to the presentinvention as it existed in Australia or elsewhere before the prioritydate of each claim of this application.

Using gravity for moving heating, circulating and ventilating air is asimple technique that has been a well understood and practiced for morethan 100 years. Hot air is less dense than cold air and will thereforetend to rise while cooler air tends to settle. However, the forceproduced in this way is very slight, and is easily overcome by frictionin ducts and by wind pressure around a building. A gravity ventilationsystem is simpler than a forced air system, requires no skilledattention, and is less expensive to install. Widespread use of gravityheating air and water systems ended mainly because such systems:

1. were difficult to install requiring large ducts and many penetrationsthrough floor slabs etc.; and

2. their installation required experienced engineers who could assess abuilding's suitability for a gravity heating systems.

Historically, the advantages of gravity heating and circulation made itparticularly advantageous for houses, small school buildings, churches,halls, etc., where a heat source may be placed near the bases of a warmair duct and where air flow resistance is low. However, unseparated airducts in a gravity ventilation system often become inefficient due tostagnation if the duct's wall becomes exposed to cooler surrounding oradjacent air that induces downdrafts within the duct which collide withrising warmer air. Gravity air ducts that allow air to circulatesimultaneously in opposite directions require very large cross-sectionslike an air well in multistory buildings. Also, it has been thought thatusing gravity for ventilation is more expensive than a fan because theamount of thermal energy required to produce a significant draft or airvelocity through a duct greatly exceeds the electrical energy requiredto power a fan. Gravity air circulation may exhibit difficulty in movinghot air into certain rooms in a building during windy weather.

Gravity air circulation may exhibit difficulty in moving hot air intocertain rooms in a building during windy weather.

BRIEF SUMMARY

The present disclosure provides an improved cooling system and, by wayof example, an improved ventilation duct.

Another potential advantage of the present disclosure is that in onealternative embodiment it allows drawing via a drain tap collectedrainwater as a backup for supplementary or emergency domestic watersupply.

Another potential advantage of the present disclosure is that where inone alternative embodiment where the water pan is filled from theMunicipal Water Mains thru a Float Valve (not illustrated in any of thefigures), the present disclosure essentially combines the functions of adomestic water reservoir tank and a building cooler into one compactcost efficient device.

In one aspect, the invention resides in a cooling system including aventilator adapted for inclusion in a building for exchanging atmospherebetween parts of the building at differing heights thereof, theventilator comprising:

a. an outer conduit adapted for being juxtaposed with at least a portionof the building, the portion being selected from a group consisting of:

-   -   i. a roof;    -   ii. a floor; and    -   iii. a wall, and

the outer conduit having a length that extends from an upper end thereofdownward to a lower end thereof;

b. an inner conduit extending substantially along the entire length ofthe outer conduit; and

c. one or more cooling tubes extending along the inner conduit,

wherein the one or more cooling tubes are connected to a pan and have afluid therein.

In another aspect, the invention resides in a coaxial ventilator adaptedfor inclusion in a building for exchanging atmosphere between parts ofthe building at differing heights thereof, the coaxial ventilatorincludes:

a. an outer conduit adapted for being juxtaposed with at least a portionthe building selected from a group consisting of:

-   -   i. a roof;    -   ii. a floor; and    -   iii. a wall, and

the outer conduit has a length that extends from an upper end thereofdownward to a lower end thereof; and

b. an inner conduit that extending substantially along the entire lengthof the outer conduit and located near the upper end of the outerconduit,

both the outer conduit and the inner conduit being open to atmospheresurrounding the coaxial ventilator and configured to allow airflowtherethrough to be reversed, whereby responsive to temperatures ofatmosphere both surrounding and within the outer conduit and the innerconduit simultaneously:

i. atmosphere about the upper end of the outer conduit enters into one(1) of two (2) conduits selected from a group consisting of:

-   -   a. the outer conduit; and    -   b. the inner conduit; and

ii. atmosphere within the coaxial ventilator exits into atmosphere aboutthe upper end of the outer conduit from one (1) of two (2) conduitsselected from a group consisting of:

-   -   a. the inner conduit; and    -   b. the outer conduit.

In a further aspect, the invention resides in a coaxial ventilatoradapted for inclusion in a building for exchanging atmosphere betweenparts of the building at differing heights thereof, the coaxialventilator comprising:

a. an outer conduit adapted for being juxtaposed with at least a portionthe building, the portion being selected from a group consisting of:

-   -   i. a roof;    -   ii. a floor; and    -   iii. a wall, and

the outer conduit having a length that extends from an upper end thereofdownward to a lower end thereof; and

b. an inner conduit extending substantially along the entire length ofthe outer conduit with an upper end located near the upper end of theouter conduit, the outer conduit having at least one (1) hole formedtherethrough for allowing an exchange of air between the outer conduitand the building in at least one (1) location along the length of theouter conduit,

both the outer conduit and the inner conduit being open to atmospheresurrounding the coaxial ventilator and configured to allow airflowtherethrough to be reversed, whereby responsive to temperatures ofatmosphere both surrounding and within the outer conduit and the innerconduit simultaneously:

i. atmosphere about the upper end of the outer conduit enters into one(1) of two (2) conduits selected from a group consisting of:

-   -   A. the outer conduit; and    -   B. the inner conduit; and

ii. atmosphere within the coaxial ventilator exits into atmosphere aboutthe upper end of the outer conduit from one (1) of two (2) conduitsselected from a group consisting of:

-   -   A. the inner conduit; and    -   B. the outer conduit.

In yet another aspect, the invention resides in a coaxial ventilatoradapted for inclusion in a building for exchanging atmosphere betweenparts of the building, at differing heights thereof, the coaxialventilator comprising:

a. an outer conduit adapted for being juxtaposed with at least a portionthe building, the portion being selected from a group consisting of:

-   -   i. a roof;    -   ii. a floor; and    -   iii. a wall, and

the outer conduit having a length that extends from an upper end thereofdownward to a lower end thereof; and

b. an inner conduit extending substantially along the entire length ofthe outer conduit with an upper end located near the upper end of theouter conduit, both the outer conduit and the inner conduit being openat the respective upper ends and lower ends thereof and configured toallow airflow therethrough to be reversed, whereby responsive totemperatures of atmosphere both surrounding and within the outer conduitand the inner conduit simultaneously:

i. atmosphere about the upper end of the outer conduit enters into one(1) of two (2) conduits selected from a group consisting of:

-   -   A. the outer conduit; and    -   B. the inner conduit; and

ii. atmosphere within the coaxial ventilator exists into atmosphereabout the upper end of the outer conduit from one (1) of two (2)conduits selected from a group consisting of:

-   -   A. the inner conduit; and    -   B. the outer conduit.

While the improved gravity ventilation duct is disclosed in the contextof being installed in a building, the ventilator is also useful forventilating tunnels, underground shelters, mineshafts, and the like.

These and other features, objects and advantages will be understood orapparent to those of ordinary skill in the art from the followingdetailed description of the preferred embodiment as illustrated in thevarious drawing figures.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional, elevational view depicting a buildinghaving a cooling system in the form of a coaxial ventilator inaccordance with the present disclosure included therein illustrating theventilator's nighttime operation in warm climate for transferring coolerair from outside a building into a lower room within the building;

FIG. 2 depicts the building of FIG. 1 illustrating day time operation ofthe coaxial ventilator in warm climate;

FIG. 3 is a cross-sectional plan view of the coaxial ventilator takenalong the line 3-3 respectively in FIGS. 1 and 2;

FIG. 4 is a cross-sectional, elevational view depicting a building inwhich an alternative embodiment of a cooling system including a pair ofcoaxial ventilators in accordance with the present disclosure ventilatetwo (2) different rooms within the building during nighttime operationin warm climate;

FIG. 5 is a cross-sectional plan view of the twin coaxial ventilators ofFIG. 4 taken along the line 5-5 therein;

FIG. 6 is a cross-sectional, elevational view depicting yet anotheralternative embodiment of a cooling system in the form of a coaxialventilator located in a multi-story building in a cold climate fortransferring warmer air from a heated room at the bottom of a building,e.g. a basement, to an upper room within the building;

FIG. 7 is a cross-sectional elevational view of a lower end of thecoaxial ventilator illustrated in FIG. 1 depicting a preferred bellshaped flaring at the lower end of the ventilator's outer conduit;

FIG. 8 is a cross-sectional elevational view of the coaxial ventilatorin accordance with the present disclosure, such as the coaxialventilator depicted in FIG. 1, that includes a pair of turbines locatedrespectively near the top and bottom thereof;

FIG. 8A shows another aspect of the coaxial ventilator according to thepresent disclosure, further including an exhaust fan;

FIG. 9 is an enlarged cross-sectional elevational view depicting ingreater detail one of the turbines depicted in FIG. 8;

FIG. 10 is a perspective view taken along the line 10-10 in FIG. 9depicting in greater detail the turbine depicted in FIG. 8;

FIG. 11 depicts a cross-sectional, elevational view of a portion of abuilding having a cooling system in the form of a coaxial ventilatorinstalled therein illustrating an alternative embodiment coaxialventilator which includes a coaxial liquid-filled thermosyphon coolingtube descending downward from a covered pan for collecting rain waterthat is located above the building's roof at the top of the alternativeembodiment coaxial ventilator and within an inner conduit thereof alonga central axis of thereof;

FIG. 12 is a cross-sectional plan view of the thermosyphon cooling tubecoaxial ventilator taken along the line 12-12 in FIG. 11;

FIG. 13 is an enlarged cross-sectional view of the thermosyphon coolingtube coaxial ventilator depicted in FIG. 11 filled with water from acovered pan located at the top of the thermosyphon cooling tube coaxialventilator;

FIG. 13A shows the bottom end of the cooling tube enlarged into a bulbtank which may have radiative heat exchanger fins or other heat exchangesurfaces at the bottom at ceiling level to additionally directlyradiatively and conductively cool the room below;

FIG. 13B illustrates the coaxial ventilator depicted in FIG. 13 that hasan alternative embodiment water filled thermosyphon cooling tube thatincludes a bulb tank located at a lower end of the thermosyphon coolingtube;

FIG. 13C shows another aspect of the coaxial ventilator of FIG. 13,further including a solar-powered exhaust fan, an exhaust wind turbine,and hanging evaporative cooling mats;

FIG. 14 is an enlarged cross-sectional plan view of the coaxialventilator taken along the lines 12-12 and 14-14 respectively in FIGS.11 and 13;

FIG. 15 is an enlarged cross-sectional view of the thermosyphon coolingtube coaxial ventilator illustrated in FIG. 13 depicting an alternativeembodiment thereof in which a tube surrounds the coaxial liquid filledcooling tube establishing an annularly-shaped space thereabout that isfilled with oil or other liquid that has a specific heat greater thanthat of water thereby increasing thermal storage capacity of thethermosyphon cooling tube coaxial ventilator;

FIG. 16 is an enlarged cross-sectional plan view of the coaxialventilator taken along the line 16-16 in FIG. 15;

FIG. 17 illustrates an alternative configuration for the thermosyphoncooling tube coaxial ventilator depicted in FIG. 13 in which both thelower portion of the covered pan and the cooling tube are filled withoil rather than water with only the upper portion of the cover pan abovethe oil being filled with water;

FIG. 18 depicts a cross-sectional, elevational view of a portion of abuilding having a cooling system in the form of a coaxial ventilatorinstalled therein that illustrates another alternative embodimentcoaxial ventilator which includes multiple liquid-filled cooling tubeseach of which respectively descends downward from the covered pan intoan annularly-shaped space located between the inner conduit and an outerconduit of the coaxial ventilator;

FIG. 19 is a cross-sectional plan view of the thermosyphon multi coolingtube coaxial ventilator taken along the line 19-19 in 18;

FIG. 20 adds to a copy of FIG. 2 a pair of optional, hollow collarflanges that encircle the coaxial ventilator respectively immediatelyabove the building's roof and also at a ceiling within the building;

FIG. 20A shows another aspect of the coaxial ventilator of FIG. 20,further including a thermoelectric cooling module;

FIG. 21 is a cross-sectional plan view of the upper hollow collar flangetaken along the line 21-21 in FIG. 20;

FIG. 22 is a cross-sectional, elevational view depicting anotherventilator in the form of a coaxial ventilator associated with thefeatures of FIG. 20 in accordance with the present disclosure;

FIG. 23 is a cross-sectional, elevational view depicting a furthercoaxial ventilator associated with the features of FIG. 20 in accordancewith the present disclosure;

FIG. 24 is a cross-sectional, elevational view depicting a furtherventilator in the form of a coaxial ventilator associated with thepresent disclosure;

FIG. 25 illustrates another ventilator in accordance with the presentdisclosure;

FIG. 26 illustrates another ventilator in accordance with the presentdisclosure;

FIG. 27 illustrates another form of a cooling system in accordance withthe present disclosure;

FIG. 28 illustrates a cross-sectional view of the cooling system shownin FIG. 27; and

FIG. 29 illustrates another form of a cooling system in accordance withthe present disclosure; and

FIG. 30 illustrates a cross-sectional view of the cooling system shownin FIG. 29.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT(S)

FIGS. 1 and 2 depict a cooling system in the form of a coaxialventilator, identified by the general reference number 20, included inthe structure of a building 22. The coaxial ventilator 20 includes anuninsulated outer conduit 24 made of a thermally conductive materialthat is juxtaposed with and, in the illustrations of FIGS. 1 and 2,passes through:

-   -   1. a roof 32;    -   2. a ceiling 34 of a warm upper story room 36; and    -   3. a floor 38 of the room 36.

The roof 32, the ceiling 34 and the floor 38 are all respective portionsof the building 22. As depicted in FIGS. 1 and 2, the outer conduit 24of the coaxial ventilator 20 has a length that extends from a flaredupper end 42 located above the roof 32 downward to a lower end 44 thatis located at a lower room 46 of the building 22 beneath the room 36. Inthe illustrations of FIGS. 1 and 2 the building 22 also includes:

-   -   1. an upper interior wall 52 a;    -   2. a lower interior wall 52 b;    -   3. a floor 54 for the room 46 for which the floor 38 of the        upper room 36 also provides a ceiling;    -   4. an upper exterior wall 56 a; and    -   5. a lower exterior wall 56 b.

The coaxial ventilator 20 also includes an inner conduit 62 made of athermally insulative material which may be flexible and/or corrugatedthat is:

-   -   1. surrounded by the outer conduit 24;    -   2. extends substantially along the entire length of the outer        conduit 24; and    -   3. is pierced by a plurality of holes 63 at locations 64 a, 64 b        and 64 c where transitions occur in temperature about the outer        conduit 24.

An upper end 66 of the inner conduit 62 is preferably located slightlybelow the top of the flared upper end 42 of the outer conduit 24.Preferably, a lower end 68 of the inner conduit 62 is similarly recessedslightly above the lower end 44 of the outer conduit 24. Consequently,the inner conduit 62 has a slightly shorter length than that of theouter conduit 24.

As depicted most clearly in FIG. 3, the presence of the inner conduit 62centered within the outer conduit 24 establishes an annularly shapedspace 72 therebetween that extends along the length of the inner conduit62. Cross-sectional areas of the inner conduit 62 and the annularlyshaped space 72 should be approximately equal with the cross-sectionalarea of the annularly shaped space 72 being slightly larger tocompensate for air friction with both the outer conduit 24 and the innerconduit 62.

While FIG. 3 depicts the inner conduit 62 as being centered within theouter conduit 24, that is not an essential requirement for the coaxialventilator 20. The coaxial ventilator 20 works well if the inner conduit62 were to be displaced to one side within the outer conduit 24. Theinner conduit 62 may not be centered within the outer conduit 24 if, forexample, the inner conduit 62 were loosely fixed or not secured at thevery center of the outer conduit 24 perhaps to facilitate fabricatingthe coaxial ventilator 20 or adjustment of inner conduit 62 etc., or ifat some locations within the building 22 the coaxial ventilator 20 isinclined, i.e. not vertical.

If the inner conduit 62 is insecurely positioned within the outerconduit 24 and the coaxial ventilator 20 is inclined, the inner conduit62 may sag or hang against a lower wall of the outer conduit 24. Undersuch a circumstance, inner conduit 62 may contact the outer conduit 24but because the inner conduit 62 is thermally insulated, i.e. does notconduct heat well, and contact area is small, little heat will betransferred from the outer conduit 24 to the inner conduit 62 therebypreserving a temperature difference between the outer and inner conduits24, 62. Accordingly, the coaxial ventilator 20 works regardless ofwhether the inner conduit 62 is at the exact center of the outer conduit24 or displaced to one side thereof.

In fact, displacing the inner conduit 62 greatly to one side of theouter conduit 24 lowers airflow resistance between the outer and innerconduits 24, 62. Displacing the inner conduit 62 to one side of theouter conduit 24 forces most of the airflow between the outer and innerconduits 24, 62 into a more cohesive “fat” crescent cross-sectionalshape, with the major portion of the air flow occurring in the “fat”center of the crescent. If most of the air flow occurs in the “fat”center of the crescent, the air flow more nearly approximates that of anideal circular cross sectional shape. Approaching more nearly to anideal circular cross sectional air flow minimizes friction with theouter and inner conduits 24, 62 in comparison with the thinner, strictlyperfectly annular shape of airflow along the annularly shaped space 72having the same cross-sectional area. To reduce friction due to stagnant“dead” space at the sharp “horned” ends of a crescent cross-sectionalshape near where the inner conduit 62 contacts the outer conduit 24, thecross-sectional area between the outer and inner conduits 24, 62 can beincreased to be slightly larger than the cross-sectional area of theinner conduit 62.

As depicted in FIG. 1, the coaxial ventilator 20 may also include acover 82 disposed above the flared upper end 42 of the outer conduit 24.Among other functions described in greater detail below, the cover 82occludes upper ends 42, 66 both of the outer conduit 24 and of the innerconduit 62 thereby preventing precipitation from entering thereinto.

The outer conduit 24 of the coaxial ventilator 20 is highly heatabsorbent and heat radiative such as being fabricated with a matt blackabsorptive and radiative surface. The inner conduit 62 is preferablymade of heat insulating material. A length of the coaxial ventilator 20passing through a warmer area of the building 22, such as the room 36 inFIG. 1, is warmed thereby heating air within a segment of the annularlyshaped space 72 that spans the room 36. As depicted in FIG. 1 by smallupwardly directed arrows in the annularly shaped space 72 below thelocation 64 b, warmer air within the annularly shaped space 72 spanningthe room 36 rises while cooler air within a segment of the inner conduit62 spanning the room 36 descends. Above a zone in which a transition intemperature about the outer conduit 24 occurs, such as that duringnighttime surrounding the location 64 a in FIG. 1, lower temperatureatmosphere about the outer conduit 24 cools air within the annularlyshaped space 72 above the roof 32. In a length of the coaxial ventilator20 being cooled by the surrounded atmosphere, as depicted in FIG. 1 bysmall downwardly directed arrows within the annularly shaped space 72above the location 64 b, cooler air descends while warmer air in theinner conduit 62 above the location 64 a rises.

At a location along the length of the coaxial ventilator 20 where risingwarmer air within the annularly shaped space 72 meets descending coolerair within the annularly shaped space 72 such as at the location 64 b,an exchange of air occurs between the annularly shaped space 72 and theinner conduit 62 with:

1. cooler descending air flowing through the holes 63 piercing the innerconduit 62 at the location 64 b into the inner conduit 62; and

2. warmer rising air flowing through the holes 63 piercing the innerconduit 62 at the location 64 b into the inner conduit 62.

After flowing from the annularly shaped space 72 into the inner conduit62, the descending cooler air continues descending within the innerconduit 62 below the location 64 b while the rising warmer air continuesrising within the inner conduit 62 above the location 64 b. As depictedin FIG. 1, in this way warmer air first rises from the room 46 in thebuilding 22 initially via the annularly shaped space 72 and subsequentlyvia the inner conduit 62 to exit the coaxial ventilator 20 at the topthereof. Conversely, cooler air initially enters the annularly shapedspace 72 at the flared upper end 42 of the outer conduit 24 to flowdownward before entering the room 46 via the inner conduit 62.

The locations 64 a, 64 b and 64c where holes 63 pierce the inner conduit62 promote formation of transition zones inside the coaxial ventilator20 where air flowing in the annularly shaped space 72 may enter into theinner conduit 62 and conversely. There exists a tendency for exchangesof air to occur between the annularly shaped space 72 and the innerconduit 62 where the coaxial ventilator 20 passes through the exteriorof the building 22 such as at the roof 32. A tendency exists for flowexchanges of air wherever a change in temperature occurs along thelength of the coaxial ventilator 20, i.e. where the coaxial ventilator20 passes from one thermal environment to another thermal environment.

The cover 82 of the coaxial ventilator 20 may be advantageouslyconfigured for evaporatively cooling air entering the flared upper end42 of the outer conduit 24 by including at the bottom thereof, spaced adistance above the flared upper end 42 of the outer conduit 24, a waterfilled pan 84. The cover 82 preferably also includes a mesh 86 thatspans between peripheries of the pan 84 and a dish-shaped top lid 88.Preferably the lid 88 is opaque and reflective to reduce solar heating.The mesh 86 prevents insects from entering the space between the pan 84and the lid 88 while permitting atmosphere about the flared upper end 42of the outer conduit 24 to circulate therethrough. A depression 89 inthe lid 88, preferably at the center thereof, with a drip hole 90 formedtherethrough, best illustrated in FIGS. 13, 15, 17 and 20, permitscollecting rain water used for filling the pan 84.

In the illustration of FIG. 2, the building 22 and the cooling system inthe form of coaxial ventilator 20 are identical to those depicted inFIG. 1. The difference between FIGS. 2 and 1 are that the small arrowswithin the annularly shaped space 72 and the inner conduit 62 differfrom those in FIG. 1 since the small arrows in FIG. 2 depict the path ofair as it flows during daytime. The principal difference betweennighttime and daytime airflows is that during daytime there is noexchange of air between the annularly shaped space 72 and the innerconduit 62. Rather, during daytime warmer air rises along the entirelength of the annularly shaped space 72 while cooler air descends alongthe entire length of the inner conduit 62.

FIGS. 4 and 5 illustrate an alternative embodiment of the presentdisclosure in which a cooling system having a pair of coaxialventilators 20 a, 20 b, in accordance herewith, ventilate two (2)different rooms 46 a, 46 b during nighttime operation. Those elementsdepicted in FIGS. 4 and 5 that are common to the coaxial ventilator 20depicted in FIGS. 1-3 carry the same reference numeral distinguished bya prime (“ ′ ”) designation. Lower segments of each of the coaxialventilators 20 a, 20 b are juxtaposed with opposite sides of theinterior wall 52 a′. As illustrated in FIGS. 4 and 5, above the roof 32′the pair of coaxial ventilators 20 a, 20 b preferably share a singlecover 82′.

FIG. 6 illustrates yet another alternative embodiment of the presentdisclosure located in a multi-story building 22″. Those elementsdepicted in FIGS. 6 that are common to the coaxial ventilator 20depicted in FIGS. 1-3 carry the same reference numeral distinguished bya double prime (“ ″ ”) designation. The building 22″ includes a basement92 having a heat source 94, i.e. a boiler or other warm appliance,located therein. Radiation and thermal convection within the basement 92warms the room 46″ through the floor 54″. As depicted in FIG. 6, acooling system in the form of coaxial ventilator 20″ extends from thebasement 92 upward to a cooler upper room 36″. Convection of warmer airvia the coaxial ventilator 20″ between the basement 92 and the room 36″warms the room 36″ while cooler air descends from the room 36″ to thebasement 92.

FIG. 7 depicts a preferred bell shaped flaring 98 of the lower end 44 ofthe outer conduit 24. Preferably, as stated previously the lower end 68of the inner conduit 62 is recessed slightly above the lower end 44 ofthe outer conduit 24. As depicted in FIG. 7, the bell shaped flaring 98,essentially forming a funnel, begins slightly above the lower end 68 ofthe inner conduit 62 and above the floor 38 of the room 36. The bellshaped flaring 98 may be advantageously shaped to exploit the Coandaeffect both for separating the upward flow of warmer air from thedownward flow of cooler air, and for drawing the rising upward flow froma larger horizontal area around the lower end 44 of the outer conduit24. The funnel formed by the preferred bell shaped flaring 98 at thelower end 44 reduces drag and turbulence. Formed in this way the bellshaped flaring 98 establishes a transition zone having a wider space forstabilizing the upward flow of warmer air and downward flow of coolerair and interference between them.

INDUSTRIAL APPLICABILITY

FIGS. 8 through 10 illustrate the coaxial ventilator 20 being usedadvantageously for power production such as generating electricity. Inthe illustration of FIG. 8, two (2) turbines 102 are located within thecoaxial ventilator 20 respectively near the top and bottom thereof. Theturbines 102 are located in sections of the coaxial ventilator 20 inwhich the inner conduit 62 lacks holes 63 and where there is maximumflow and pressure differential to drive the turbines 102. While FIG. 8depicts only two (2) turbines 102, it is readily apparent that dependingupon construction details a single coaxial ventilator 20 may includemore or fewer than two (2) turbines 102.

As depicted in FIGS. 9 and 10, inner turbine blades 104 upon whichcooler air descending through the inner conduit 62 impinges preferablyslant in a direction opposite than outer turbine blades 106 upon whichhotter air rising through the annularly shaped space 72 impinges.Configured in this way, both the descending cooler air and the risinghotter air urge the turbine 102 to rotate in the same direction.Preferably, to advantageously exploit the Coriolis effect the slantdirection of the inner turbine blades 104 and the outer turbine blades106 differs depending upon whether the turbine 102 is located in theNorthern Hemisphere or Southern Hemisphere. Advantageously, the slant ofthe inner turbine blades 104 and the outer turbine blades 106 may changeautomatically thereby adapting them for differing air flow pressure andvelocities occurring throughout the day.

Referring back to FIG. 8, during daylight hours solar heating of airwithin the room 46 and the outer conduit 24 provides energy for drivingthe turbines 102 by heating and expanding air therein. The air pressureincrease associated with solar heating and expansion enhances theupdraft in annularly shaped space 72 between the outer conduit 24 andthe inner conduit 62 before the air escapes from the upper end 42. Notethat solar radiation impinging upon the outer conduit 24 heats airwithin the annularly shaped space 72. Accordingly, for this particularapplication it is advantageous to increase the height of the coaxialventilator 20 that extends above the roof 32. If during night time theair flows within the coaxial ventilator 20 reverse the turbines 102correspondingly reverse rotation which still provides power forgenerating electricity.

Rotation of the turbine 102 by hotter air impinging upon the outerturbine blades 106 rotates the inner turbine blades 104 thereby drawingcooler air into the inner conduit 62 to thereby increase the naturaldescent of cooler air within the inner conduit 62 and compress airwithin the room 46. After air flow within the coaxial ventilator 20becomes stable for instance during daytime, the increased flow ratesproduced by solar heating will be sufficient to overcome any slight backpressure due to increased air pressure within the room 46.

Daytime power production efficiency may be increased by including a nonreturn valve, not illustrated in FIGS. 8 10, at the lower end 68 of theinner conduit 62. Such a non return valve increases daytime efficienciesby preventing reverse flow through the inner conduit 62. However,including such a non return valve also prevents the flow directionswithin the coaxial ventilator 20 from reversing for producing powerduring the night.

While less preferred and not illustrated in FIGS. 8-10, the turbines 102may instead include two (2) independent sets of contra-rotating blades104, 106 both of which sets slant in the same direction. Because suchinner turbine blades 104 and outer turbine blades 106 rotate in oppositedirections, generating electricity with a single generator requirescoupling the blades 104, 106 together with a mechanical transmission.Alternatively, electricity might be generated using two separategenerators respectively coupled independently to the inner turbineblades 104 and to the outer turbine blades 106.

Alternatively, if electricity is supplied to the turbines 102 ratherthan being drawn therefrom, then the turbines 102 can be usedadvantageously for boosting air flow through the coaxial ventilator 20.

Another aspect of coaxial ventilator 20 is illustrated in FIG. 8A andfurther includes a weatherproof exhaust or circulation fan 300,positioned above the water pan 84, for increasing the evaporative heatloss rate from the water pan 84, and thereby increasing the coolingcapacity of the coaxial ventilator 20, by creating a wind current acrossthe water surface. This embodiment is particularly advantageous forincreasing evaporative heat loss on windless days and could lower thetemperature of the water in the water pan 84 by as much as, for example,an additional 8° F. (4° C.). The weatherproof exhaust fan 300 could bepowered by solar photovoltaic cells (not shown) mounted on the lid 88.Other methods for increasing the evaporative rate from the water pan 84include, but are not limited to, spraying the water from the water pan84 upwards into the air or sprayed upwards onto wetted fabric mats, orby natural water capillary wicking action upwards from the water pan 84onto fabric or mesh mats suspended above, and partially submerged into,the water pan 84, thereby increasing the evaporative surface area (seefor example, FIG. 13B, discussed hereinbelow). Small water pumps usedfor spraying the water out of the water pan 84 could be powered by solarphotovoltaic cells (not shown) mounted on the lid 88. The sprayed water,having been cooled by evaporative cooling, would then drip back downinto the water pan 84, thereby reducing the temperature of water in thewater pan 84.

An alternative embodiment of a cooling system in the form of coaxialventilator 20 depicted in FIGS. 11, 12, 13, 13A, 13B, 13C and 14 furtherincludes a liquid-filled thermosyphon cooling tube 124 that dependsbeneath a pan 84 into an inner conduit 62 of the coaxial ventilator 20.In the illustrations of FIGS. 11, 12, 13, 13A, 13B, 13C and 14, thecooling tube 124 descends along a central axis of the coaxial ventilator20 to be thereby surrounded by the inner conduit 62. Disposed asdepicted in FIGS. 11, 12, 13, 13A, 13B, 13C and 14, the cooling tube 124advantageously increases contact area for heat exchange coolingsignificantly between:

-   -   1. water evaporating from a pan 84 located at the top of the        coaxial ventilator 20; and    -   2. air within the coaxial ventilator 20 about the liquid-filled        thermosyphon cooling tube 124.

In the embodiment depicted in FIGS. 11, 12, 13, 13A, 13B, 13C and 14,the cooling tube 124 is filled with water 126 drawn from the pan 84. Adrain tap 128 located at the bottom of the cooling tube 124 permitsdrawing collected rainwater as a backup for supplementary or emergencydomestic water supply. The cooling tube 124 is preferably made of copperor similarly high thermal conductivity material, and maybe be finned orcorrugated with heat conducting surfaces to increase the surface areafor heat exchange, or alternatively be of semi-permeable surfaces toincrease the surface area for water evaporation cooling.

Adding a liquid-filled thermosyphon cooling tube 124 that includes aperforated inner return tube, such as that described in U.S. Pat. No.6,014,968 and hereby incorporated by reference as though fully set forthhere, to the coaxial ventilator 20 depicted in FIGS. 1-3 effectivelyelongates the heat exchange area of the evaporative cooling water-filledpan 84. Effectively elongating the heat exchange area of the evaporativecooling water-filled pan 84 in this way increases cooling capacity of acoaxial ventilator 20 without significantly increasing the overall sizeof the coaxial ventilator 20. Extending the heat exchange area of thecoaxial ventilator 20 by including the thermosyphon cooling tube 124therein increases heat exchange efficiency between air within thecoaxial ventilator 20 and evaporative cooling water-filled pan 84.

FIG. 13B illustrates the coaxial ventilator 20 depicted in FIG. 13having an alternative embodiment water filled thermosyphon cooling tube124. The cooling tube 124 depicted in FIG. 13B differs from the coolingtube 124 depicted in FIG. 13 by:

-   -   1. extending further downward beneath a lower end of the inner        conduit 62; and    -   2. having an enlarged lower end that forms a bulb tank 182.

As depicted in FIG. 13B, the bottom of the bulb tank 182 may includeprojecting heat exchanging fins 184 for cooling surrounding atmosphere.The bulb tank 182 advantageously enlarges the cooling surface area andstorage capacity of the cooling tube 124, as well as facilitating directradiative, conductive and convective cooling into atmosphere surroundingthe bulb tank 182 such as to the room 46 depicted in FIG. 13A similar toa radiative cooling ceiling panel. This increases the storage capacityof the cooling tube 124, and betters the coaxial ventilator 20 when usedfor water storage for the building 22 perhaps thereby avoidingadditional expense of a separate water storage tank. When used for waterstorage, the lower end of the bulb tank 182 includes a drain tap 186,either alone or in addition to the drain tap 128. The bulb tank 182 asdepicted in FIG. 13B and described above can be adapted for use in otherconfigurations of the coaxial ventilator 20 disclosed herein whichinclude the cooling tube 124.

As also illustrated in the embodiment of the coaxial ventilator 20depicted in FIG. 13B, the pan 84 atop the coaxial ventilator 20 may alsoadvantageously include an inlet float valve 192 connected to a watermain supply not separately depicted in the FIG. Attaching the inletfloat valve 192 to the pan 84 ensures that the pan 84 at all timesremains full of water, and cooler water flowing thereinto advantageouslyreduces the temperature of water in the pan 84. The embodiment of thecoaxial ventilator 20 depicted in FIG. 13B also includes an outlet pipe196 that advantageously permits drawing warm water from the pan 84.

In hot climates during daytime, drawing water from the outlet pipe 196at the top of the pan 84 enables supplying preheated warm water:

-   -   1. for household use; or    -   2. to a household's water heater.

Moreover, cooler refill water entering the pan 84 through the inletfloat valve 192 lowers the temperature of water in the pan 84 therebymaintaining cooling efficiency of the water pan 84. Otherwise, on hotafternoons excess heat collected in the water pan 84 may not bedissipated quickly enough thru evaporation. The presence of a warm waterlayer in the water pan 84 may reduce evaporative cooling of the waterdue to mixing of water cooled by evaporation sinking below the water'ssurface.

As depicted in FIG. 13B the embodiment of the coaxial ventilator 20shown there may also advantageously include, respectively, a heatexchanger coil 202 located in the pan 84, and a heat exchanger coil 206located in the bulb tank 182. At various times of the day asappropriate, the heat exchanger coils 202 and 206 are useful for warmingor cooling pressurized fluid flowing respectively through the heatexchanger coils 202 and 206. For example, during very hot afternoonspreheated warm water can be drawn from the pan 84 via the outlet pipe196 or thru the heat exchanger coil 202 in the pan 84 before beingheated further in a water heater not depicted in any of the figures.

Similarly, when excess cool water is present in the bulb tank 182 theheat exchanger coil 206 may be used for precooling a household airconditioner's refrigerant before it enters the conditioner's compressoror condenser not depicted in any of the figures. Within the coaxialventilator 20, water heated in this way rises through the cooling tube124 to the pan 84 where it may heat fluid flowing through the heatexchanger coil 202. Heat transferred in this way from the bulb tank 182to the pan 84 reduces energy consumed by a household's air conditionerand water heater.

FIG. 13C shows another aspect of the coaxial ventilator 20 depicted inFIG. 13A further including a vertical axis exhaust wind turbine 400, aweatherproof exhaust fan 402, and evaporative cooling wetted fabric matsor mesh 404. While both the wind turbine 400 and the exhaust fan 402accelerate evaporative airflows across the water pan 84 surface toincrease evaporative heat loss, the coaxial ventilator 20 could alsoinclude evaporative cooling wetted fabric mats or mesh 404 that aresuspended above and partially submersed in the water pan 84. The fabricmesh 404 is wetted by way of capillary wicking action, or spraying bywater pumps (not shown), thereby increasing the evaporative coolingsurface area and thus, increasing the evaporative cooling rate. The windturbine 400, the exhaust fan 402, and the water pumps could be poweredby photovoltaic cells and/or batteries (not shown) that can be mountedto either the lid 88 of the coaxial ventilator 20, to a top surface ofthe wind turbine 400, or positioned at another suitable location. Theexhaust fan 402 and the exhaust wind turbine 400 both function toaccelerate the evaporative air flows across the water surface,exhausting the humid air up and out of the water pan 84 area and drawingin fresh dry air, thereby increasing the evaporative cooling rate. Theblades of the exhaust wind turbine 400 are positioned at an angle facingoutwards, such that the blades catch the wind, causing the exhaust windturbine to rotate by the force of the wind. The blades may beaerodynamically formed such that the movement of the blades pushes airoutwards horizontally, creating a low pressure area behind the blades onthe inside of the exhaust wind turbine, drawing humid air out from abovethe water pan 84. The exhaust fan 402 and exhaust wind turbine 400 caninclude propeller and impeller blades, respectively, that are freelymovable when they are not powered, so that they will spin freely,relative to one another, and not impede operation of each other when oneis working and the other is not. Alternatively, the propeller blades ofthe exhaust fan 402 and the impeller blades of the exhaust wind turbine400 could be coupled together so that they both turn in unison, whenappropriately geared. Accordingly, when the impeller of the wind turbine400 and propeller of the exhaust fan 402 are coupled together, the solarphotovoltaic cells and/or batteries could be used to drive both theexhaust fan 402 as well as the exhaust wind turbine 400 while onlyproviding power to one of the wind turbine 400 or exhaust fan 402.Similarly, wind could drive both the exhaust wind turbine 400 as well asthe exhaust fan 402. It should be noted that the coaxial ventilator ofthe present embodiment need not include both the wind turbine 400 andthe exhaust fan 402, and if there is no wind turbine 400, the exhaustfan 402 could be operated in either an exhaust or intake mode.

The coaxial ventilator 20 depicted in FIGS. 11, 12, 13, 13A, 13B, 13Cand 14 passively, cost effectively, and space efficiently usesevaporating rain water to capture and store nighttime “coolness” for useduring mornings and afternoons when it is most needed. During dryweather, any rain water collected in the pan 84 can be augmented byconnecting a float valve controlled piped water supply to the upperevaporative cooling water-filled pan 84 (not illustrated in any of theFIGS.). While evaporative cooling occurs continuously throughout anentire day, however temperatures are coolest at night, i.e. over 10hours of nighttime evaporative cooling on average. Consequently, thereexists ample time during that 10 hour interval to cool water in the pan84 down to nighttime temperatures.

However, holding a sufficient quantity of water both for daytime coolingneeds, particularly to store nighttime cooling capacity, and forproviding sufficient evaporative heat exchange surface area, requires aquite large, heavy and unwieldy water-filled pan 84 that is locatedabove a building's roof. Frequently, without a large pan 84 there isinsufficient thermal storage capacity to extend nighttime “coolness”well into the afternoons, and insufficient heat exchange area totransfer heat into air descending down into the coaxial ventilator 20.

If a coaxial ventilator 20 is being used for supplying water to thebuilding 22, the drain tap 128 may connect to the cooling tube 124 atany height along the length of the cooling tube 124. As those skilled inthe art will recognize, connecting the drain tap 128 to the cooling tube124 higher along the cooling tube 124 nearer to the pan 84 reduces thewater pressure at the drain tap 128 in comparison with water pressure ata drain tap 128 connected to the cooling tube 124 lower along thecooling tube 124 nearer to the bulb tank 182. The location of the draintap 128 along the length of the cooling tube 124 also affects thetemperature of water drawn from the drain tap 128. During daytime, waterdrawn from a drain tap 128 connected to the cooling tube 124 higheralong the cooling tube 124 nearer to the pan 84 will, in general, bewarmer than water drawn from a drain tap 128 connected to the coolingtube 124 lower along the cooling tube 124 nearer to the bulb tank 182.During daytime, the warmest water may be drawn from a drain tap 128located nearest to the pan 84. In a hot climate, to preserve cold waterstored overnight undisturbed at the bottom of the bulb tank 182 forcooling the building 22, it is advantageous to avoid drawing water fromthe drain tap 186 but rather to draw water from a drain tap 128 locatedat an intermediate height along the cooling tube 124.

FIGS. 15 and 16 depict an alternative embodiment of the coaxialventilator 20 depicted in FIGS. 11, 12, 13, 13A, 13B, 13C and 14. In theembodiment depicted in FIGS. 15 and 16 the water-filled thermosyphoncooling tube 124 below the pan 84 is surrounded by a tube 132illustrated by a dashed line in those FIGs. The tube 132:

-   -   1. preferably has a circular cross-section;    -   2. preferably is made of copper or similarly high thermal        conductivity material to enhance heat exchange between liquids        filling the tube 132 and the cooling tube 124; and    -   3. may be flexible, finned or corrugated.

The tube 132 establishes an annularly shaped space 134 around thecooling tube 124 that is preferably filled with oil 138 or other liquidhaving a specific heat greater than that of water. In this way liquidfilling the annularly shaped space 134 being in close thermal heatexchange contact with the cooling tube 124 increases thermal storagecapacity of the coaxial ventilator 20.

FIG. 13A shows the bottom end of the cooling tube enlarged into a bulbtank which may have radiative heat exchanger fins or other heat exchangesurfaces at the bottom at ceiling level to additionally directlyradiatively and conductively cool the room below. That is in addition tothe cooled air convection taking place. It enlarges the cooling surfacearea and water or oil storage capacity of the cooling tube 124, 126 andthe annularly shaped space 134, as well as allowing direct radiativecooling to take place into the room below, thus increasing the coolingefficiency. The bulb tank can be adapted to all other Coaxial Ventilatorconfigurations shown variously with cooling tube 124, 126, and annularlyshaped space 134, etc. Enlarging the water storage capacity helps whenthe Coaxial Ventilator is also used as a water storage tank (waterstorage tank function not applicable to FIG. 17 where oil is the storagemedium) for the building or house, thus saving on the cost of a normalhousehold or building water storage tank. In this case when the bulbtank forms part of the water storage tank capacity (in addition to thecooling tube 124, 126, and the evaporative water pan 84 above) anadditional water draw off pipe or drain tap 128 would be drawn off thebulb tank at the lowest level of the bulb tank at ceiling level to beused in the rooms below (additional ceiling level water draw off pipenot shown in FIG. 13A).

As illustrated by dashed lines in FIGS. 15 and 16, the performance ofthe thermosyphon cooling tube coaxial ventilator 20 illustrated in thosefigures can be further enhanced by extending the annularly shaped space134 along the length of the thermosyphon cooling tube 124 upward andoutward beneath the pan 84. This extension of the tube 132 upward andoutward permits the liquid having a specific heat greater than that ofwater to contact the bottom of the pan 84.

In this way the thermosyphon cooling tube coaxial ventilator 20 depictedin FIGS. 15 and 16 having the double layer pan 84 and cooling tube 124filled on the inside with water 126 that is surrounded by and separatedfrom the liquid that fills the tube 132 and that has a specific heatgreater than that of water:

-   -   1. permits using a smaller diameter water-filled pan 84; and    -   2. further increases the cooling storage capacity of the coaxial        ventilator 20.

Furthermore, the thermosyphon cooling tube coaxial ventilator 20depicted in FIGS. 15 and 16 simplifies suspending the coaxialthermosyphon cooling tube coaxial ventilator 20 in comparison withsupporting an alternative coaxial ventilator 20 having a larger roof topwater-filled pan 84.

While the cooling tube preferably is a thermosyphon cooling tube 124,the inner return tube included in a thermosyphon cooling tube 124 may beomitted although this reduces cooling tube efficiency. If the returntube of the cooling tube 124 is omitted, then its outer tube must:

-   -   1. have a larger diameter than that of the cooling tube 124 if        the cooling tube is to achieve the same amount of heat transfer;        or    -   2. if of the same outer diameter as the cooling tube 124, have a        shorter length than that of the thermosyphon cooling tube 124        and can provide only a lesser amount of heat transfer due to        stagnation inefficiencies and inversion layer formation that        results from the tube's smaller diameter.

In yet another alternative embodiment of the coaxial ventilator 20depicted in FIG. 17 the lower portion of the covered pan 84 and thecooling tube 124 are filled with oil 138 rather than water. The coolingtube 124 and the pan 84 are first filled with oil 138 up toapproximately half the depth of the pan 84. The pan 84 above the oil isthen filled with:

-   -   1. rain water collected through the lid 88; or    -   2. water from a piped supply controlled by a float valve (not        illustrated in any of the figures).

In the configuration depicted in FIG. 17, the drain tap 128 is not usedfor drawing collected rainwater. Rather, the drain tap 128 at the bottomof the cooling tube 124 is now opened only when the oil has to bedrained off for servicing the cooling tube 124, or for changing of theoil, probably once every three or four years.

The oil chosen for use in the alternative embodiment depicted in FIG.17:

-   -   1. must be immiscible in water;    -   2. must be heavier than water;    -   3. should not evaporate at room temperatures;    -   4. should remain liquid and free flowing at room and ambient        temperatures; and    -   5. have a much higher specific heat capacity than water.

For such an oil, water in the pan 84 floating on the oil and cooled byevaporation sinks and contacts the oil to thereby cool the oil below.

Layering water for evaporation above oil, with oil extending down intothe thermosyphon cooling tube 124 including the inner return tube,increases the cooling capacity of the cooling tube 124 by:

-   -   1. using oil to store the “coolness;” while    -   2. still permitting the water to evaporate and cool the oil        below.

And this is done without incurring additional structural cost of adouble walled pan 84 and/or a double walled cooling tube as was shown inFIGS. 15 and 16 etc., or otherwise having to enlarge the cooling tubeand coaxial ventilator 20. For the embodiments of the coaxial ventilator20 depicted in FIGS. 15 through 17, material forming the cooling tube124 and the surrounding tube 132 must be impervious so the liquidtherein cannot evaporate or leak out.

The illustrations of FIGS. 18 and 19 depict yet another alternativeembodiment of a cooling system in the form of coaxial ventilator 20which includes multiple liquid-filled cooling tubes 124. Similar to thecooling tube 124 depicted in FIGS. 11 and 12, each of the cooling tubes124 respectively descends downward from the covered pan 84. Howeverrather than descending along the central axis surrounded by the innerconduit 62, the multiple cooling tubes 124 depicted in FIGS. 18 and 19descend into an annularly shaped space 72 located between the innerconduit 62 and an outer conduit 24 of the coaxial ventilator 20. In theembodiment of the coaxial ventilator 20 depicted in FIGS. 18 and 19, thecooling tubes 124 may have the same configuration as any of the variousdifferent types of cooling tubes that are described in greater detailabove and depicted in FIGS. 11 through FIG. 17.

Referring now to FIGS. 20 and 21, the outer conduit 24 of the coaxialventilator 20 depicted in those FIGs. is encircled by a pair ofoptional, hollow collar flanges 142 respectively located:

-   -   1. above the roof 32 of the building 22; and    -   2. at a ceiling 34 within the building 22 through which the        coaxial ventilator 20 passes.

Encircling the outer conduit 24 with the collar flanges 142 establishesan open, annularly shaped space 144 between the outer conduit 24 and theroof 32 and ceiling 34 respectively about the coaxial ventilator 20. Theannularly shaped spaces 144 facilitate ventilating spaces within thebuilding 22 both below and above each of the collar flanges 142.

At the roof 32, attached to a hole through the roof 32, the collarflange 142 includes a collar flashing 152 that extends upward a distanceabove the roof 32 sufficient to impede rainwater from splashing from theroof 32 into the annularly shaped space 144. Because the upper end ofthe collar flashing 152 is smaller in diameter than the pan 84, theupper opening of the collar flashing 152 about the outer conduit 24 isinherently somewhat shielded from the entry of rainwater. Where thecoaxial ventilator 20 penetrates the ceiling 34, the collar flange 142includes an open annular collar 156 that passes through the ceiling 34and extends a short distance above and below the ceiling 34.

The upper end of the collar flange 142 extending above the roof 32preferably includes flap shutters 162 that may be closed both to blockairflow through the collar flange 142 and the entry of rainwaterthereinto. Correspondingly, the collar flange 142 extending through theceiling 34 preferably includes dampeners 166 that may be rotated to aclosed position to block airflow through the collar flange 142.

Both collar flanges 142 respectively located at the roof 32 and at theceiling 34 when open provide additional ventilation that reduces anybuild up or stagnation of warm air about the coaxial ventilator 20 atthe roof 32 and the ceiling 34. Including the collar flanges 142 aboutthe coaxial ventilator 20 advantageously keeps the immediate vicinity ofthe coaxial ventilator 20 cooler thereby improving its efficiency intransferring cool air from the pan 84 to the room 36 below without theair becoming unduly heated.

As illustrated in FIG. 20, the coaxial ventilator 20 depicted in any ofthe various FIGs. may also include as set of dampeners 172 located atthe lower end of the coaxial ventilator 20. In climates which experienceboth heat in summer and cold in winter, both the shutters 162 and thedampeners 166 as well as the dampeners 172 are left open during summerso hot air can escape from the building 22, and closed in winter toconserve heat within the building 22.

FIG. 20A shows another aspect of the coaxial ventilator of FIG. 20,further including a thermoelectric cooling module 500. FIG. 20A showsanother method of filling the water pan 84 with water that can be usedin locations where is it difficult to bring a piped water supply to fillthe water pan 84. As shown in FIG. 20A, a thermoelectric Peltier coolingmodule or other cooling module 500 is located at the bottom of the lid88 to condense atmospheric water vapor into water droplets which thendrip into and fill water pan 84. Solar photovoltaic cells could be usedto provide power the cooling module 500 and could be mounted on the topsurface of lid 88, or positioned at another suitable location. Thephotovoltaic cells could also be used to charge batteries (not shown),thereby extending the power supply of the cooling module 500 into thenight, when solar power is no longer available. Additionally, a lowerend of the cooling module 500 could extend into and below the surface ofthe water in the pan 84 to provide additional cooling capacity bydirectly cooling the water pool itself.

FIG. 22 illustrates the outer conduit 24 using a space in the form ofthe roof cavity (i.e. the area between the roof 32 and ceiling 34) tochannel airflow to and/or from the ends of the outer conduit 24. Theroof cavity therefore acts, in part, as the outer conduit 24, with thecollar flanges 142 establishing an annular space 144 at the roof 32 andceiling 34 levels. This arrangement saves costs, due to a reduction inthe amount of materials, but some flow inefficiencies are introduce dueto some air flow mixing in the roof cavity. However, air flow is stillable to readily pass by the lower end of the inner conduit 62 into/fromthe roof cavity. That is, at least part of the air may flow in asubstantially linear direction from near the lower end of the innerconduit to the upper end of the outer conduit 24, or vice versa.

FIG. 23 illustrates a coaxial ventilator with an outer conduit 24′having perforations (i.e. holes) in its outer wall. This allows air toflow from the roof cavity into the inner portion of the outer conduit24′ and vice versa. The roof cavity therefore acts as an expanded outerconduit 24′.

FIG. 24 illustrates a further cooling system in the form of coaxialventilator with, in a similar manner to FIG. 22., the outer conduit 24using a space in the form of the roof cavity to channel airflow. It willbe appreciated that in other alternative forms perforations may beincluded in the outer conduit 24, in a similar manner to FIG. 23.Cooling tubes 124, 126 extend from the water pan 84 in FIG. 24 and arelocated within the inner conduit 62. The cooling tubes 124, 126 extendbeyond the lower end of the inner conduit 62 and this may allow, forexample, the discharge valve 128 to be easily accessible.

The cooling tubes 124, 126 bias the flow in the inner conduit 62 in adownwards manner when the cooling tubes 124, 126 are sufficiently coolerthan the outer conduit 24. On this basis, if the water in the coolingtubes 124, 126 is not of sufficiently lower temperature to influence orbias the air flow in the conduits, the influence of the cooling tubes124, 126 is less effective. Accordingly, the air flows are reversiblebased upon temperature differential horizontally across the coaxialventilator.

FIG. 25 illustrates another cooling system, in accordance with thepresent disclosure, in the form of ventilator 21. The ventilator 21 issimilar in construction to the coaxial ventilators 20 and, as such, likenumbering has been used. However, the following key features are noted.

In a similar manner to the ventilator 20 in FIGS. 22 and 24, theventilator 21 includes an outer conduit 24 that uses at least part ofthe roof cavity to channel airflow. In this regard, a portion of theouter conduit 24 is connected to the roof 32 and provides a passage fordirecting airflow to and/or from the roof cavity. An inner conduit 62extends from near an upper end of the outer conduit 24 to a positionthat is offset from the ceiling 34. That is, a lower end of the innerconduit 62 terminates at a position that is unaligned with part of thebuilding 22 that is adjacent thereto. In other words, the lower end ofthe inner conduit 62 is not coterminous with the outer conduit 24 and/orwith the ceiling 34 thereabove.

The cooling tubes 124, 126 of the embodiment shown in FIG. 25 areconnected to pan 84 and extend from a position above the inner conduit62 to a position that is offset from ceiling 34. Separately, the coolingtubes 124, 126 extend below the end of the outer conduit 24 and belowthe lower end of the inner conduit 62. In this regard, the dischargevalve 128 is located below the end of the inner conduit 62. The coolingtubes 124, 126 are regulated in FIG. 25 in such a manner that they aresufficiently cooled to ensure that air moves down the inner conduit 62to the room 36. The modified outer conduit 24 (using the roof cavity)and the shortened inner conduit (in relation to the extended coolingtubes 124, 126) save material costs and reduce roof structural loading(avoiding the costs for further reinforcement). The protruding lower endof the cooling tubes 124, 126 provides extra cooling surface forradiative, convective and conductive cooling to the room 36.

With the above in mind, an advantage of offsetting the inner conduit 62and cooling tubes 124, 126 from the ceiling 34 is that the cool downwardflowing air can be focused in areas where it is most needed. By way ofexample, cool air entering high ceiling rooms may result in cool airdissipating before it reaches a suitable area to cool patrons of abuilding. On this basis, by offsetting the inner conduit 62 and coolingtubes 124, 126 from the ceiling 34 and extending them into to a suitablearea in the room (e.g., 2.5 metres above the floor), the cooling effectin the room 36 may be more effective.

Furthermore, the embodiment shown in FIG. 25 also provides cost savings,and roof structural load savings in a similar manner to FIGS. 22 and 24,by reducing the amount of materials associated with the outer conduit34. As outlined above, savings may also be employed with regard to thematerial associated with the inner conduit 62. This is particularlyadvantageous in warehouses, shopping malls, factories and so forth whichhave large roof spans and/or high ceilings and, as such, targeting ofcooling to patrons and personnel is preferably required.

FIG. 26 illustrates another ventilator 21′ in accordance with thepresent disclosure. The ventilator 21′ is substantially similar to theventilator 21, shown in FIG. 25, but a lower portion of the ventilator21′ does not engage with the ceiling 26. That is, as the roof 32 formsthe ceiling 34, the lower portion of the inner conduit 62 does notengage with the ceiling 34. In a similar manner to the ventilator 21,the cooling tubes 124, 126 of the ventilator 21′ extend below the lowerend of the inner conduit 62. The arrangement of the ventilator 21′assists in focusing the cooler downward stream air at a suitable levelbelow the high ceiling 34 and allows savings on material costs and thestructural loading on the roof 32.

FIG. 27 illustrates a cooling system 21″ that is based upon theventilator 21′, shown in FIG. 26, but the inner conduit 62 has beenremoved. In a similar manner to FIGS. 22 to 26, the collar flanges 142,152 form an annular opening 144 in the roof 32. The annular opening 144is sized wide enough so that the upwards (exhaust) warm air can flowaround its perimeter whilst the downwards fresh air, cooled by the waterpan 84 and cooling tubes 124, 126, can flow down around the centralportion of the annular opening 144 without the warm and cool flowssubstantially mixing. It will be appreciated that the annular opening144, with a single outer conduit, will have to be wider than theprevious embodiments to achieve similar flow rates but, in buildingswhere large openings or air wells can be allowed, this is a simple, lowcost and low structural weight solution. With the above in mind, thewater pan cover 82 will also have to be sized wide enough to preventrain from falling into the annular opening 144 or alternatively, thecooling system of water pan 84 and cooling tube 124, 126 can be placedin an air well in a building. FIG. 28 illustrates a cross sectional viewof the embodiment shown in FIG. 27.

The cooling system 21′″ shown in FIG. 29 includes the cooling tubes 124,126 in combination with the pan 84. The pan 84 includes an openingexposing it to atmospheric conditions. The cooling tubes 124, 126 areconfigured to engage with the roof 32 and support the pan 84 thereabove.The cooling system 21′″ in FIG. 29 is suitable for applications where,for instance, the air above roof 32 may be close to an exhaust (e.g. afume chimney). Similarly, for sound insulation purposes, or where theroom below is air conditioned and the humidity is controlled etc., itmay be more suitable to use the cooling system 21′″ shown in FIG. 29.Moreover, where there are already many other openings in the roof 32and/or walls nearby for ventilation, an opening around the cooling tube124,126 may not be required. To further appreciate the cooling system21′″ shown in FIG. 29, FIG. 30 illustrates a cross sectional view of thecooling system in FIG. 29.

Although the present invention has been described in terms of thepresently preferred embodiment, it is to be understood that suchdisclosure is purely illustrative and is not to be interpreted aslimiting. Consequently, without departing from the spirit and scope ofthe disclosure, various alterations, modifications, and/or alternativeapplications of the disclosure will, no doubt, be suggested to thoseskilled in the art after having read the preceding disclosure.Accordingly, it is intended that the following claims be interpreted asencompassing all alterations, modifications, or alternative applicationsas fall within the true spirit and scope of the disclosure.

It is to be understood that, throughout the description and claims ofthe specification, the word “comprise” and variations of the word, suchas “comprising” and “comprises”, is not intended to exclude otheradditives, components, integers or steps.

1. A cooling system including a ventilator adapted for inclusion in abuilding for exchanging atmosphere between parts of the building atdiffering heights thereof, the ventilator comprising: a. an outerconduit adapted for being juxtaposed with at least a portion of thebuilding, the portion being selected from a group consisting of: i. aroof; ii. a floor; and iii. a wall, and the outer conduit having alength that extends from an upper end thereof downward to a lower endthereof; b. an inner conduit extending substantially along the entirelength of the outer conduit; and c. one or more cooling tubes extendingalong the inner conduit, wherein the one or more cooling tubes areconnected to a pan and have a fluid therein.
 2. The cooling system ofclaim 1, wherein the inner conduit extends beyond the outer conduit andis offset from the portion of the building such that it terminates in aroom.
 3. The cooling system of claim 1, wherein the one or more coolingtubes extends along an inner portion of the inner conduit.
 4. Thecooling system of claim 1, wherein the one or more cooling tubes extendbelow an end of the inner conduit.
 5. The cooling system of claim 1,wherein at least part of the ventilator is configured to supportadditional equipment.
 6. The cooling system of claim 5, wherein theadditional equipment is selected from the group consisting of lighting,fans, displays and combinations thereof.
 7. The cooling system of claim1, wherein the inner conduit has at least one hole formed therethroughfor allowing an exchange of air.
 8. The cooling system of claim 1,wherein the upper end of the outer conduit is locatable above the roofof the building, and the ventilator further comprises a cover disposedabove the upper end of the outer conduit that occludes upper ends bothof the outer conduit and of the inner conduit, thereby preventingprecipitation from entering thereinto while simultaneously permittingatmosphere to enter thereinto.
 9. The cooling system of claim 8, whereinthe cover includes mesh that spans between peripheries of the pan and alid for: i. barring entry of insects into the cover, while ii.permitting atmosphere to circulate therethrough, whereby volatile liquidin the pan evaporatively cools atmosphere entering the coaxialventilator.
 10. The cooling system claim 1, wherein the outer conduit isconfigured to use a cavity to assist in moving air flow.
 11. The coolingsystem of claim 10, wherein the cavity is in the form of a roof cavityin the building.
 12. The cooling system of claim 1, wherein at least oneof the one or more cooling tubes is semi-permeable, thereby providing asurface area thereon for evaporation cooling.
 13. The cooling system ofclaim 1, wherein the pan is semi-permeable, thereby providing a surfacearea thereon for evaporation cooling.
 14. The cooling system of claim 1,wherein (i) at least one of the one or more cooling tubes issemi-permeable, and (ii) the pan is semi-permeable, thereby providing asurface area thereon for evaporation cooling.
 15. A cooling system forinclusion in a building, the cooling system comprising: one or morecooling tubes that are configured to be supported by a roof and extendtherethrough into a building space; a pan supported by the one or morecooling tubes, the pan being configured to receive a fluid therein thatassists in providing fluid to the one or more cooling tubes, whereinthermosiphon cooling of the fluid in the one or more cooling tubesassists in cooling the building space.
 16. The cooling system of claim15, wherein the one or more cooling conduits are configured in a mannerthat they are sufficiently cooled to assist in moving air down the innerconduit.
 17. The cooling system of claim 15, wherein at least one of theone or more cooling tubes is semi-permeable for providing a surface areathereon for evaporation cooling.
 18. The cooling system of claim 15,wherein the pan is semi-permeable for providing a surface area thereonfor evaporation cooling.
 19. The cooling system of claim 15, wherein (i)at least one of the one or more cooling tubes is semi-permeable, and(ii) the pan is semi-permeable, thereby providing a surface area thereonfor evaporation cooling.
 20. The cooling system of claim 15, wherein: a.the one or more cooling tubes and a lower portion of the pan is filledwith a liquid that is: i immiscible in water; and ii. heavier thanwater; and b. water fills a portion of the pan above the liquid.
 21. Thecooling system of claim 15, further comprising at least one of avertical axis exhaust wind turbine and an exhaust fan, wherein thevertical axis exhaust wind turbine or exhaust fan is used to acceleratethe air flow over the pan to increase its cooling efficiency.
 22. Thecooling system of claim 15, further comprising an evaporative coolingmat suspended above and partially submerged in the pan.
 23. The coolingsystem of claim 22, wherein the evaporative cooling mat is wetted by wayof spraying by pumps.
 24. The cooling system of claim 15, furthercomprising a cooling module partially submergible in water held in thepan when the pan is full, the cooling module condensing atmosphericwater vapor into water droplets, thereby filling the water pan, anddirectly cooling the water in the pan when the pan is full.
 25. Thecooling system of claim 15, further comprising photovoltaic cells forproviding power to one or more devices of the cooling system.
 26. Thecooling system of claim 15, wherein the fluid is open to atmosphericpressure.